1. Field of the Invention
The present invention relates to an electronic musical instrument with a pitch alteration function which permits alteration of a pitch specified by a pitch designating operation to another pitch in accordance with preset pitch alteration width data. More particularly, this invention relates to an electronic musical instrument with a pitch alteration function suitable for playing a trill performance.
2. Description of the Related Art
An electronic musical instrument has been known which permits a musical performance by alternately specifying a pitch designated by a pitch designating operation through a keyboard and a pitch altered by operation of a half-tone trill key or a full-tone trill key (i.e., the pitch half tone or full tone higher than the former pitch).
According to such an electronic musical instrument, however, a possible trill performance is limited to such an extent that the pitch designated by a pitch designating operation through the keyboard is changed to another pitch, a half pitch or a full pitch higher, by operation of the half-tone trill key or full-tone trill key provided in advance. The width of pitch alteration that can be changed by operation of each trill key is simply a half tone or full tone length. As a solution to this restriction, it has been proposed to provide a 1.5-tone trill key, a two-tone trill key, etc. in addition to the mentioned, original two trill keys. An increase in the quantity of trill keys with different pitch alteration widths not only increases the manufacturing cost accordingly, but also complicates the pitch altering operation as the proper trill key should be operated in accordance with the desired pitch alteration width.